A common talking point among Web developers, whether we’re revamping an existing site or starting from scratch, are the assumed profiles of typical users. We try to predict their:

Background, education & culture

Specific interest in our branded topics

Motivation(s) for visiting our site

“Value system” for Web content

We also try to grasp how these and similar attributes will affect their response our message—right now, today, in real time.

Carried out methodically, this line of thought can help us develop sites that acquire, retain, position, compete or share. That is, provided our predictions are based on more than vague generalities couched in specific numbers.

That’s because we need to know what people do—not what numbers do—the people who visit our site. If your theory of marketing derives from a study you read, instead a study you led, you need to wonder how definitive your “findings” are.

Statistical variables vs the variability of human nature.But even assuming a best-case scenario, there’s still one more behavioral category that, as I see it, is usually overlooked: The natural variability within one and the same person. Take a quick look in the mirror and realize that, unless you have some rare form of obsessive-compulsive disorder, your behavior operates within a range.

Though you may usually follow a certain routine when you, say, visit a Web site, there will be times when you break the mold.

So we must assume that users we identify as eager to absorb our branded message will not always care to make an in-depth exploration of our content. No matter what other targeted attributes our site visitors may have, they’ll occasionally fall into one of two categories:

Swimmers

Divers

The difference is depth of involvement on a visit-by-visit basis. And it strikes me that, considering how jam-packed a typical Web site is, paying attention to your customers’ alter egos just might have a shot at lowering the volume on the boing-boing sound associated with rising bounce rates.

Swimmers skim for essentials.In this context, “paying attention” means staging your message with a two-tiered approach. By all means, build your Web presence so it can accommodate whatever attention mode your audience might be in at the moment. For Swimmers, you’ll need a user path that delivers your complete, albeit “essential” message along the smallest possible trajectory.

That is, chuck out the marketing speak, the promotional manipulation, celebrity endorsement—or that flaming gibberish about JD Powers and Associates—and just tell your Swimmers what you want them to do. In other words:

Make your digital presentation action-oriented.

Whether it’s view a 15-second video, activate an animated bar graph, call a sales rep, take a survey, solve a silly puzzle, or enter a sweepstakes—give your short-attention-span visitors something very easy to do, and make it rewarding.

No, not to you, to your visitor. At least, I assume the only reason you’ve posted something online is that you have something rewarding to deliver. If not, no amount of SEO, strategic brainstorming or blog-squinting can save you.

Divers delve for reasons to care.On the flip side of this duality are the Divers, people actually eager to “learn more” about your brand. But be warned: To make their deep dive meaningful, you must create a clear, efficient path for them to reach the specifics—and only those specifics they’re actually interested in. Otherwise, they might run out of oxygen and click away.

Keep in mind the attributes underlying a typical viral video: the razor sharp honing of a concise message by a tantalizing concept. You want people to listen? Give them a reason to care—and a feel for the emotional logic of your offering.

Now, can anybody actually do this, or am I asking for the moon?

Well, a step on the path I propose is on display at TED.com, the Anti-Tea Party if ever there was one. Click around on its navigation and see how effortlessly the site enables you to filter, fuss and fidget with the content until you strike the balance that strikes your fancy. My personal favorite is the “SURPRISE ME” button—for people with a real interrest who don’t know where to go, but want to get there fast.

Here’s an example of what a what can happen when we pick our heads up from the pixels and think about people. Sure, just adopting the nav logic at TED.com isn’t going to tip the balance in your favor. But if you can catch the viral thought process it suggests, you might come closer to developing a Web space both Swimmers and Divers can comfortably inhabit.